1. Technical Field
The present disclosure relates to a vehicle headlight device mounted to a vehicle etc., and particularly to the vehicle headlight device which can suitably illuminate an area within which the vehicle is stoppable, with a simple configuration.
2. Related Art
Headlight devices mounted to vehicles, such as automobiles, are typically configured to be provided with a plurality of lighting systems having different light distribution characteristics (e.g., different illuminating areas), for example, caused by high beam (driving beam) headlights and low beam (passing beam) headlights, of which light sources are selectively turned on and off according to a traveling state of the vehicles. Recently, Adaptive Front-lighting System (AFS) that automatically changes the illuminating area, for example, according to the traveling state of the vehicles has been proposed. For example, Japanese Unexamined Patent Application Publication (JP-A) No. 2014-008913 discloses a headlight device that reduces a glare to oncoming automobile(s), pedestrian(s), etc. by changing the intensity and angle of the illumination according to a traveling speed of the vehicles.
As disclosed in JP-A No. 2014-008913, only an area within which the vehicle is stoppable can be illuminated by changing the angle of illumination according to the traveling speed of the vehicle. Thus, it can be prevented to induce a vehicle operator's unnecessary gaze caused by illuminating even an area unnecessary for a determination the vehicle, and to increase a burden of the vehicle operator. However, if at least some of the light sources and optical systems are configured to be movable so that their optical axes are pivotable at least in vertical directions, and the illuminating area is changed by actuators which drive the light sources and optical systems, the configuration of the headlight device becomes complicated, and weight and costs increase.